A ruined mine on Bodmin Moor in Cornwall: investors are backing a venture to extract lithium, a vital component of electric car batteries, across the countyAlamy

A venture attempting to extract lithium, a vital component for electric car batteries, from a swathe of land across Cornwall has completed its first cash raising and brought in outside investors from the mining industry.

Cornish Lithium was created in May 2016 by Jeremy Wrathall, the chief executive, and his wife, Louise, a geologist.

This March he stepped down as head of natural resources in London at Investec, the broker, to devote all his time to the venture.

Cornwall is more associated with tin mining and the Toronto-listed Strongbow Resources, which last year bought the historic South Crofty tin mine out of administration, is involved with the venture.

The presence of lithium in hot salt brines in Cornwall has been known since the 1860s but…